Design choices for the prediction and optimization stage of finite-set model based predictive control

The interest in applying model-based predictive control (MBPC) for power-electronic converters has grown tremendously in the past years. This is due to the fact that MBPC allows fast and accurate control of multiple controlled variables for hybrid systems such as a power electronic converter and its load. As MBPC is a family of possible controllers rather than one single controller, several design choices are to be made when implementing MBPC. In this paper several conceptual possibilities are considered and compared for two important parts of online Finite-Set MBPC (FS-MBPC) algorithm: the cost function in the optimizations step and the prediction model in the prediction step. These possibilities are studied for two different applications of FS-MBPC for power electronics. The cost function is studied in the application of output current and capacitor voltage control of a 3-level flying-capacitor inverter. The aspect of the prediction model is studied for the stator flux and torque control of an induction machine with a 2-level inverter. The two different applications illustrate the versatility of FS-MBPC. In the study concerning the cost function firstly the comparison is made between quadratic and absolute value terms in the cost function. Comparable results are obtained, but a lower resource usage is obtained for the absolute value cost function. Secondly a capacitor voltage tracking control is compared to a control where the capacitor voltage may deviate without cost from the reference up to a certain voltage. The relaxed cost function results in better performance. For the prediction model both a classical, parametric machine model and a back propagation artificial neural network are applied. Both are shown to be capable of a good control quality, the neural network version is much more versatile but has a higher computational burden. However, the number of neurons in the hidden layer should be sufficiently high. All studied aspects were verified with experimental results and these validate the simulation results. Even more important is the fact that these experiments prove the feasibility of implementing online finite-set MBPC in an FPGA for both applications

20 years of DIEAP flap breast reconstruction : a big data analysis

With every hospital admission, a vast amount of data is collected from every patient. Big data can help in data mining and processing of this volume of data. The goal of this study is to investigate the potential of big data analyses by analyzing clinically relevant data from the immediate postoperative phase using big data mining techniques. A second aim is to understand the importance of different postoperative parameters. We analyzed all data generated during the admission of 739 women undergoing a free DIEAP flap breast reconstruction. The patients' complete midcare nursing report, laboratory data, operative reports and drug schedule were examined (7,405,359 data points). The duration of anesthesia does not predict the need for revision. Low Red Blood cell Counts (3.53 x 10(6)/mu L versus 3.79 x 10(6)/mu L, p < 0.001) and a low MAP (MAP = 73.37 versus 76.62; p < 0.001) postoperatively are correlated with significantly more revisions. Different drugs (asthma/COPD medication, Butyrophenones) can also play a significant role in the success of the free flap. In a world that is becoming more data driven, there is a clear need for electronic medical records which are easy to use for the practitioner, nursing staff, and the researcher. Very large datasets can be used, and big data analysis allows a relatively easy and fast interpretation all this information

(Se) Représenter autrement les personnes avec des troubles psychiques. Analyser - nuancer - déstigmatiser

Ce rapport examine comment l’on peut arriver à donner une image plus nuancée des personnes avec des troubles psychiques. Dans un premier temps, les chercheurs de la KU Leuven ont cartographié les frames et counterframes qui définissent les représentations liées aux personnes avec des troubles psychiques dans notre société. Ils ont ainsi étudié comment ces représentations participent à la persistance de la stigmatisation des personnes dans cette situation. Ensuite, les chercheurs ont testé, via une enquête effectuée auprès d’un échantillon représentatif de la population belge, les effets de l'utilisation de contreframes « déproblématisants» dans la communication au sujet des personnes avec des troubles psychiques. Enfin, les chercheurs ont examiné dans quelle mesure ces frames et counterframes sont utilisés par les professionnels du secteur de la santé mentale. Ils ont étudié comment la connaissance et la compréhension de ces mécanismes pouvait réduire le tabou et la stigmatisation qui entourent, encore aujourd’hui, les troubles psychiques. (Source: Site Web www.kbs-frb.be)nrpages: 126status: publishe

Een inspirerende kijk op de beeldvorming over personen met psychische problemen

Dit rapport gaat na hoe een meer genuanceerd beeld van personen met psychische aandoeningen tot stand kan worden gebracht. De onderzoekers van de KU Leuven brengen in kaart welke frames en counterframes het beeld van personen met psychische problemen in onze maatschappij bepalen, en hoe dit het stigma over dit onderwerp in stand houdt. Via een opinieonderzoek bij een representatieve staal van de Belgische bevolking worden de effecten van het gebruik van ‘deproblematiserende’ counterframes in de communicatie eveneens onderzocht. Ten slotte wordt nagegaan in welke mate deze denkkaders aanwezig zijn onder professionals uit de sector van de geestelijke gezondheidszorg zelf, en hoe kennis van en inzicht in deze mechanismen het maatschappelijk stigma op psychische problemen kunnen wegwerken. (Bron: website kbs-frb.be)nrpages: 124status: publishe

Lumbar flap versus the gold standard : comparison to the DIEP flap

Background: The lumbar artery perforator flap is an excellent free flap for breast reconstruction whenever the deep inferior epigastric perforator (DIEP) flap is not an option. The main indication is a lack of abdominal bulk, often seen in young BRCA-positive women seeking prophylactic amputation and immediate reconstruction. Methods: Between October of 2010 and July of 2016, a total of 661 free flap breast reconstructions were performed. The authors retrospectively analyzed patient demographics, perioperative parameters, and secondary corrections. Results: Seventy-six lumbar artery perforator flaps were retained and compared with a cohort of 560 DIEP flaps. The average body mass index for lumbar patients was 23.8 kg/m(2), with a mean age at operation of 46.3 years. Average body mass index for DIEP patients was 25.2 kg/m(2), with a mean age at operation of 48.8 years old. Lumbar artery perforator flap weight was 504 g (range, 77 to 1216 g) on average versus 530 g (range, 108 to 1968 g) for the DIEP flaps. The amount of corrective procedures performed was very similar in both cohorts: 13 percent of the lumbar artery perforator and 12 percent of the DIEP patients underwent no procedures, 62 percent in both groups underwent one procedure, and 25 percent versus 27 percent underwent two or more procedures. Lipofilling was performed in 48 percent of lumbar artery perforator flaps compared with 57 percent of the DIEP flaps (p = 0.14). Mean volume injected was 98.0 cc and 125.1 cc for lumbar artery perforator and DIEP flaps, respectively (p = 0.071). Conclusions: The lumbar flap is a good alternative whenever a DIEP flap is not possible. Bilateral autologous reconstruction is possible even in very thin patients, and secondary corrections are comparable to those for the DIEP

Male-to-female gender affirmation surgery : breast reconstruction with Ergonomix round prostheses

People with gender dysphoria are becoming more prevalent and more universally accepted. Social, hormonal, and surgical gender transition are able to substantially improve their quality of life. Various gender affirmation surgery (GAS) options are available to address gender dysphoria in the male-to-female (MtF) population, including facial and chest feminization, body contouring, and genital surgery. While hormone replacement therapy may result in some degree of breast development, it is often insufficient to effectively result in an adequate female-like breast contour. The creation of a female chest is generally the first surgical step in the transition. The primary aim of this manuscript is to describe the surgical technique with ergonomix round prostheses used at our high-volume GAS center and to point out how anatomical differences between trans-female and cis-female patients impact surgery. Furthermore, we provide an overview of the demographic data and postoperative outcomes

Nipple reconstruction in autologous breast reconstruction after areola-sparing mastectomy

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Comparing the lumbar and SGAP flaps to the DIEP flap using the BREAST-Q

Background: The deep inferior epigastric artery perforator (DIEP) flap is the gold standard in autologous breast reconstruction. When the abdomen is not available, alternative donor sites can be found at the buttock, the lumbar region, or the thighs. These flaps are referred to as second-choice flaps. This study compares the superior gluteal artery perforator (SGAP) flap and the lumbar artery perforator (LAP) flap to the DIEP flap using patient-reported outcomes. Methods: A retrospective study was performed reviewing the records of 417 women who underwent a free flap breast reconstruction with either a DIEP, an LAP, or an SGAP flap, between 2006 and 2018. Patients were asked to fill out the BREAST-Q questionnaire, and patient-reported outcomes were analyzed and correlated to the demographic information. Results: The response rate was 54.5 percent, with 50 LAP, 153 DIEP, and 25 SGAP flap patients participating. When questioned about their satisfaction with breasts and satisfaction with outcome, all three procedures were rated similarly high. When comparing the physical well-being of the donor site and appearance of the donor site, LAP flap patients reported significantly lower scores than DIEP and SGAP flap patients. Conclusions: Patients who undergo LAP or SGAP flap breast reconstruction seem similarly satisfied with the appearance and outcome of their free flap breast reconstruction compared with DIEP flap patients. The donor-site morbidity and its impact on the patient's well-being in SGAP and LAP flap patients have been underestimated. Despite more donor-site discomfort, the LAP and SGAP flaps are feasible alternatives whenever the DIEP flap is not possible